/**
* V-dialogDrag 弹窗拖拽
* Copyright (c) 2019 ruoyi
*/

export default {
	bind(el: {querySelector: (arg0: string) => any}, binding: {value: any}, vnode: any, oldVnode: any) {
		const {value} = binding;
		if (value == false) {
			return;
		}

		// 获取拖拽内容头部
		const dialogHeaderEl = el.querySelector('.el-dialog__header');
		const dragDom = el.querySelector('.el-dialog');
		dialogHeaderEl.style.cursor = 'move';
		// 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
		const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);
		dragDom.style.position = 'absolute';
		dragDom.style.marginTop = 0;
		let {width} = dragDom.style;
		if (width.includes('%')) {
			width = Number(document.body.clientWidth) * (Number(width.replace(/\%/g, '')) / 100);
		} else {
			width = Number(width.replace(/\px/g, ''));
		}

		dragDom.style.left = `${(document.body.clientWidth - width) / 2}px`;
		// 鼠标按下事件
		dialogHeaderEl.onmousedown = (e: {clientX: number; clientY: number}) => {
			// 鼠标按下，计算当前元素距离可视区的距离 (鼠标点击位置距离可视窗口的距离)
			const disX = e.clientX - dialogHeaderEl.offsetLeft;
			const disY = e.clientY - dialogHeaderEl.offsetTop;

			// 获取到的值带px 正则匹配替换
			let styL: number; let styT: number;

			// 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
			if (sty.left.includes('%')) {
				styL = Number(document.body.clientWidth) * (Number(sty.left.replace(/\%/g, '')) / 100);
				styT = Number(document.body.clientHeight) * (Number(sty.top.replace(/\%/g, '')) / 100);
			} else {
				styL = Number(sty.left.replace(/\px/g, ''));
				styT = Number(sty.top.replace(/\px/g, ''));
			}

			// 鼠标拖拽事件
			document.onmousemove = function (e) {
				// 通过事件委托，计算移动的距离 （开始拖拽至结束拖拽的距离）
				const l = e.clientX - disX;
				const t = e.clientY - disY;

				const finallyL = l + styL;
				const finallyT = t + styT;

				// 移动当前元素
				dragDom.style.left = `${finallyL}px`;
				dragDom.style.top = `${finallyT}px`;
			};

			document.onmouseup = function (e) {
				document.onmousemove = null;
				document.onmouseup = null;
			};
		};
	},
};
